A photo taken prior to an exhibit at The Franklin Institute shows the thumb that was later taken from a statue at The Franklin Institute in Philadelphia.(Photo: Photo provided)

PHILADELPHIA – A court fight is underway in the case of a party-goer who allegedly took a thumb from a centuries-old statue at an exhibit of terra-cotta warriors.

But this battle isn’t over Michael Rohana, a Delaware man awaiting trial on federal charges in connection with the digit’s disappearance during a boozy party in a museum.

It focuses instead on the scene of the crime, Philadelphia’s Franklin Institute.

Rohana’s attorneys want the museum to provide extensive records about its security arrangements, particularly those in place when some 700 people attended an Ugly Sweater Party on the night of Dec. 21, 2017.

A federal prosecutor is opposing that request, arguing the records could encourage jurors to blame The Franklin Institute for the thumb-napping.

In a flurry of recent filings, two public defenders also argue the charges against Rohana are excessive.

They challenge the government’s estimate of the thumb’s value, a key factor in two of the three felony charges.

And they question whether the thumb was “under the care, custody and control” of a museum – another key element – when it was taken from the Cavalryman, a statue unearthed at the tomb of China’s first emperor.

A terracotta statue lost his thumb to an intruder at the Franklin Institute in Philadelphia, authorities say.(Photo: Photo provided)

The public defenders note The Franklin Institute’s statement, shortly after the incident became public, that a security contractor did not follow “standard closing procedures” on the night of the party.

"This lapse in securing and protecting the terra-cotta warriors, during a party in which beer and wine were being sold and served, suggests that The Franklin Institute was not, in fact, operating as a 'museum’ … but rather, an after-hours nightclub that just happened to take place in a museum," says a Feb. 27 filing.

It says Rohana and two other guests were able to enter a darkened exhibit space more than two hours after the holiday-season party got underway.

"Needless to say, when Mr. Rohana in his ugly green sweater entered the Terracotta Warriors of the First Emperor exhibit to explore it, he was intoxicated,” the filing allows.

It contends the museum’s security records might help show Rohana's actions were "more consistent with vandalism than with the specific intent to steal."

A party-goer is accused of taking a thumb from an exhibit of terracotta statues on loan from China to the Franklin Institute in Philadelphia.(Photo: Photo provided)

The prosecution alleges Rohana, while alone in an unlocked and unguarded exhibit, snapped a selfie with the Cavalryman, then snapped off the statue’s left thumb and put it in his pocket.

A museum staffer noticed the thumb was missing more than two weeks later. An investigation led FBI agents on Jan. 13 to Bear, Delaware, where Rohana lives with his parents.

"When asked if he had anything in his possession he wanted to turn over to the FBI, Mr. Rohana stated he had a finger from a museum,” a court record says. Rohana retrieved the thumb from a desk drawer in his bedroom, it says.

The Cavalryman was part of a traveling exhibit that appeared at the Philadelphia museum from Sept. 30, 2017, to March 4, 2018. It included 10 sculptures created about 2,200 years ago and discovered in 1974 by farmers digging a well.

The public defenders also want documents about alcohol sales at the museum, saying evidence of intoxication “may show that Mr. Rohana did not have the intent to commit the offense.”

The defense team — Catherine Henry and Nancy MacEoin of the Federal Community Defender Office in Philadelphia — are seeking a subpoena that would require the Franklin Institute to turn over the documents.

They say an attorney for the museum has not complied with their earlier request for multiple records, including any communications between the Franklin Institute and Chinese authorities.

Public defenders for a man accused of taking a thumb from a statue want security records from Philadelphia's Franklin Institute.(Photo: Courtesy of The Franklin Institute, Philadelphia, PA.)

But a federal prosecutor has asked U.S. District Judge Petrese Tucker to bar “any evidence or argument” that Rohana’s conduct “should be excused or ignored because of any alleged failure or negligence of the Franklin Institute, its employees or contractors."

“This case is about (Rohana's) guilt or innocence," Assistant U.S. Attorney K.T. Newton said in a March 8 motion opposing the request for security records.

“It is not about any alleged negligence by the Franklin Institute. Nor is it about any accidental damage to objects exhibited at the Franklin Institute,” said Newton. She asserted the museum’s security information would be “irrelevant and unduly prejudicial to the government.”

“This is nothing more than a cover for the use of this information for jury nullification,” asserted the prosecutor, who also objected to the release of any reports pertaining to accidental damage to Franklin Institute exhibits “by visitors and/or contractors.”

Newton’s motion said jury nullification occurs when a jury deliberately rejects evidence or refuses to apply the law “because the jury wants to send a message about some social issue … or because the result dictated by law is contrary to the jury's sense of justice, morality or fairness."

Tucker, who has set an April 1 trial date, has yet to rule on the dispute.

Henry and MacEoin also contend the prosecution can’t prove the thumb is worth more than $5,000. That’s the legal threshold for two charges against Rohana – the theft and concealment of an object of cultural heritage from a museum.

He’s also accused of taking the thumb across state lines.

While the prosecution estimates the thumb is worth $150,000 based on fair market value, the defense team argues that number is “pure speculation.”

"Because the thumb is the property of the Chinese government and … cannot be bought or sold in the commercial marketplace, the government would be unable to offer proof of the actual market price,” a defense filing says.

The defense does not contest the Cavalryman’s insured value of $4.5 million. But it contends that figure does not prove “the market value of the individual thumb.”